Abstract

Microparticles injected into a plasma have been shown to deplete the free electron population as electrons are collected through the process of microparticles charging to the plasma floating potential. However, these charged microparticles can also act to scatter electromagnetic signals. These experiments investigate microwave penetration through a previously impenetrable overly dense plasma layer as microparticles are injected and the physical phenomena associated with the competing processes that occur due to electron depletion and microwavescattering. The timescales for when each of these competing processes dominates is analyzed in detail. It was found that while both processes play a significant and dominant role at different times, ultimately, transmission through this impenetrable plasma layer can be significantly increased with microparticle injection.

This work was supported by U.S. Naval Research Laboratory base funds. This work was also supported by the National Science Foundation (Grant No. PHY-0953595). This research was performed while the author (Eric D. Gillman) held a National Research Council Research Associateship Award at the U.S. Naval Research Laboratory.